Rock Island County, Illinois - Then and Now

The area was originally inhabited by the Sac and Fox Indians whose principal villages were within the present limits of Rock Island County. United States soldiers came here in 1816 when Fort Armstrong was built on Rock Island in the Mississippi River. The county prior to its organization was included in the jurisdiction of Jo Daviess County, Illinois. The first land entry was October 19, 1829. The Illinois Legislature organized Rock Island County in 1833, and the county seat was designated as Stephenson (later known as Rock Island) in 1835. Rock Island was a military prison for confederate soldiers during the Civil War. There were 12,212 prisoners and 1,960 deaths. The Confederate Cemetery is next to the Rock Island National Cemetery.  
The Past and Present of Rock Island County, ILL. 1877

With the Mighty Mississippi River to the north and west and the Rock River flowing through the center, Rock Island County offers a varied landscape ranging from rich agricultural fields to rolling bluffs. With low housing costs, exceptional health care, quality schools and a wide range of recreational activities and tourist attractions, it's no wonder Rock Island County is home to nearly 150,000 residents and thousands of visitors each year. Rock Island County is part of the Quad Cities Metropolitan Area of approximately 360,000 residents, nestled along the Mississippi River on the Illinois/Iowa border between Chicago, Illinois and Des Moines, Iowa. The area is served by interstates I-80, I-88, I-74, I-280, several major state highways and the Quad City International Airport.
https://www.rockislandcountyil.gov/369/About-Rock-Island-County